HIRINGWO - Editorial

[cherry0697]

For brute force partition run two nested loops and remove a[i] and a[j] from the array and insert (a[i] * a[j] ) into the array. Repeat the process until you get the desired size.

Spoiler

// left is number of times we need to compress the array

 void partition(int left, vector <ll> v1){
  if(left==0){
    ll temp=0;

    for(auto itr: v1){
      temp+=itr;
    }

    sum=min(sum,temp);
    return;
  }

  for(ll i=0;i<v1.size();i++){
    for(ll j=i+1;j<v1.size();j++){
      vector <ll> v2;

      v2.pb(v1[i]*v1[j]);
      for(ll k=0;k<v1.size();k++){
        if(k!=i && k!=j){
          v2.pb(v1[k]);
        }
      }

      partition(left-1,v2);
    }
  }
}